I have a 4 year old white Macbook that I don't plan to replace until it breaks down. My order of preference for a replacement would be:
1. 13" Macbook Pro
2. 21.5" iMac
3. Mac mini
I personally think #1 and 2 at ~$1200 are Apple's best bang for the buck. I paid ~$950 for my Macbook and am pleased with how long it's lasted (including 2 years overseas) with only having to replace the battery last year.
The OG MacBook was a total tank. Mine is still ticking since Aug '06, my friend's is going after 3-4 years as well. Liquid is the only thing that kills those things, nothing else will. Drops, shock, heat, cold, nothing touches them. But spill a drop of water on them and you are screwed.